Experimental study on seismic behavior of high strength steel composite Y-type eccentrically braced frames.

High strength steel composite Y-type eccentrically braced frame is a new dual resistance structural system, in which the link is made from steels with low yield strength and the others are made from high strength steel. In order to study the seismic behavior, four one-bay and one-story 1/2 scaled plane specimens were tested under monotonic and cyclic loading respectively. According to the length of link, the specimens were classified into two group; flexural yielding and shear yielding. The failure modes and the main seismic behavior indices of specimens with various link lengths of energy disspation were analyzed. The results indicate that this new structural system is good at energy dissipation and ductility. The bearing capacity of shear yielding specimens is higher than flexural yielding specimens, the ductility of the former is better than the latter, and the energy absorbed in the former is bigger than the latter at the same displacement. In cyclic testing, the main failures of shear yielding specimens were concentrated at links, while the other parts of eccentrically braced frame kept in elastic status. This kind of structure is an excellent dual resistance system and easy to rehabilitate after earthquake. [ABSTRACT FROM AUTHOR]